WebResource.axd not working with Internet Explorer 11

Question

We\'re testing our websites for the new Windows 8.1 IE 11 browsers classic and metro.
There is a Javascript file embedded in WebResource.axd.

Answer 1

We were finally able to resolve the issue by installing the hotfix http://support.microsoft.com/kb/2600088 (32bit or 64 bit) mentioned by Richard and more then run the aspnet_regbrowsers -i .
Thanks all for the solutions. Didn't want to take the claim for the answer but maybe people might not find it in comments.

Answer 2

Richard's workaround above:

Setting Page.ClientTarget = "uplevel" in the Page_Init event.

is the correct one; you need to disable the use of User-Agent sniffing to get ASPNET to send IE11 the proper script blocks. http://msdn.microsoft.com/en-us/library/system.web.ui.page.clienttarget.aspx

Unfortunately, it turns out that the patch they took to enable IE10 doesn't work properly with IE11 (because the IE team significantly changed the IE user agent string, removing the MSIE token by default). So, another patch for ASP.NET was shipped in June 2013. See https://stackoverflow.com/a/18651133/126229